JP3774246B2 - Container sealing surface inspection - Google Patents

Abstract

Apparatus for inspecting the sealing surfaces (36) of containers (22) that includes a light source (42) positioned to direct a narrow beam (44) of light energy at an acute angle onto the sealing surface of a container as the container is rotated about its central axis. A light sensor (46) is disposed to receive the narrow beam (45) of light energy reflected from the sealing surface, and provides an output signal that varies as a function of position of incidence of the reflected light beam on the sensor. The sensor is coupled to associated electronics (52) for providing information indicative of container height, and a signal for controlling separation of a container from the conveyor system when height of the container, warp or dip of the container sealing surface, or cocked finish at the container exceeds predetermined standards. <IMAGE>

Description

[0001]
[Industrial application fields]
The present invention relates to a method and apparatus for inspecting containers, and in particular, measuring changes in level at the sealing surface of the container.
[0002]
[Prior art]
U.S. Pat. No. 3,313,409 discloses an apparatus for inspecting glass containers through which a single star wheel transports containers through a series of inspection stations. At one of the inspection stations, a selected dimensional parameter for each container causes the container to contact a roller coupled to the sensor such that the sensor provides an output signal that varies as a function of the amount of change in the container parameter. And inspected by rotating the container about its central axis. In particular, the height of the container, the distortion and downward inclination of the sealing surface, and the upward inclination of the container mouth are measured by a roller that contacts the container sealing surface as the container rotates. The roller is coupled to a linear variable differential transformer (LVDT) sensor and provides an analog electrical signal indicating the level deviation or displacement at the sealing surface. These signals are sent to the appropriate electronic device, and if the measurement signal deviates from a predetermined standard value and specification, the reject plunger is energized to separate the container from the transfer line.
Although the inspection system disclosed in the above-mentioned patent and assigned to its assignee has gained substantial commercial success, improvements remain desirable. Rollers that contact the container sealing surface are susceptible to mechanical wear. These rollers can also contaminate the sealing surface. The dimensions of these rollers limit the dimensions of the associated containers that can be used and the level (resolution) of the level variation that can be detected. Moving parts require maintenance and repair. It is a general object of the present invention to provide an apparatus and dimensions for inspecting a sealing surface of a container for variations in the level of the container sealing surface that addresses and overcomes the deficiencies in the art.
[0003]
[Problems to be solved by the invention]
An object of the present invention is to provide an apparatus and a method for measuring a level change amount of a sealing surface of a container using an electro-optic technique in which a weighing device does not contact a measurement surface. Another object of the present invention is to provide a method and apparatus with the above characteristics that achieve the above objectives while being economically satisfactory and reliable over an extended operating life. Still another object and specific object of the present invention is to measure the height of the container at the sealing surface, measure strain and downward inclination at the sealing surface, and measure the upward inclination of the container mouth. It is to provide a non-contact method and apparatus.
[0004]
[Means for Solving the Problems]
The present invention contemplates a method and apparatus for directing a narrow beam of light energy onto a sealing surface and electro-optically measuring the level change in the sealing surface of the container by the beam being reflected by the optical sensor. Is. The sensor provides an electrical output that varies as a function of the incident position of the light beam reflected on the sensor. Thus, any change in the level of the container sealing surface will result in a corresponding change at the point or position where the reflected light beam impinges on the sensor, so that the sensor changes as a linear function of the sealing surface level. Supply output signal.
An apparatus for inspecting a sealing surface of a container mouth according to a presently preferred embodiment of the present invention is arranged to direct a narrow beam of light energy on the sealing surface of the container as the container rotates about its central axis. Light source included. An optical sensor is arranged to receive a narrow beam of light energy reflected by the sealing surface and provides an output that varies as a function of the incident position of the reflected light beam on the sensor. The sensor is coupled to the associated electronic device, information indicating the height of the container, and a standard value for which the height of the container, the distortion or downward inclination of the sealing surface of the container, or the upward inclination of the container is predetermined. A control signal is provided for separating containers from the conveyor system.
[0005]
The light source and light sensor of the preferred embodiment of the present invention are disposed above the sealing surface of the container and are oriented with respect to each other and with respect to the container sealing surface so that they are incident on and reflected from the container sealing surface. The resulting beam lies in a plane perpendicular to the sealing surface. In one embodiment of the present invention, two light source / sensor pairs are disposed on the laterally opposed surfaces of the container, and each sensor has an output signal that varies as a function of the level of the container sealing surface in close contact with the sensor. Supply. The two sensors are coupled to an electronic circuit and measure the level change of the sealing surface as a combined function of the two sensor output signals. Thus, the downwardly inclined and upwardly inclined container mouths of the sealing surface can also be identified and measured as a function of the difference between the sensor output signals, while the distorted sealing surface is the sum of the sensor output signals. It can also be identified and measured as a function. The height of successive containers transferred through the inspection station and the amount of change in height can also be measured as a function of the output of either or both of the above sensors.
The invention, together with its additional objects, features and advantages, will be best understood from the following description, the appended claims and the accompanying drawings.
[0006]
【Example】
Referring to FIG. 1, the conveyor 20 typically includes a star wheel (not shown) and a sliding plate 21 and is located at the source of the shaped container to provide a continuous container 22 into the location of the sealing surface inspection station 24. And connected. The star wheel conveyor container inspection arrangement is disclosed, for example, in the aforementioned U.S. Pat. No. 3,313,409. A bottle rotator 26, such as a drive roller, is arranged to contact each container 22 at station 24 and rotate the container about its central axis 25 when the conveyor holds the container in a fixed position. The The encoder 28 is connected to the container rotation mechanism for providing a signal indicating the increment of the container rotation. A detector 30 such as a switch is arranged to provide a signal to the station 24 indicating the presence of the container 22.
[0007]
In the practice of the present invention shown in FIG. 1, the container 22 comprises a molded glass bottle with a cylindrical body 32 and a generally cylindrical neck 34 protruding upwardly from a body shoulder 35. The container mouth includes an upper portion of the neck 34 that terminates in an axial surface finish cap sealing surface 36, which is inspected according to the present invention. The helical thread 38 is integrally formed in the outer surface of the mouth wall surrounding the container mouth, or a lip or shoulder 40 is formed on the outer surface of the mouth wall to cover it and add a cap to the container. The cap skirt is crimped as usual. The present invention is directed to a method and apparatus for inspecting the level height and variation of the sealing surface 36 for fitting the cap.
A light source 42, such as a laser or incandescent light source, is placed above the sealing surface 36 of the container 22 of the station 24 and is directed at an acute angle on the sealing surface 36 to direct a narrow collimated beam 44 of light energy downward. Oriented to. A camera 46 is also placed over the sealing surface 36 of the container 22 of the station 24 and is directed to receive the beam 45 reflected from the sealing surface 36. The camera 46 includes a focusing lens 48 and an optical sensor 50 that provides an electrical output signal that displays not only the incidence of reflected light energy on the sensor, but also the location of the incidence on the sensor. The information processing device 52 receives a signal from the detector 30 that indicates the presence of the container 22 at the inspection station 24 and a signal from the encoder 28 that indicates the increase in container rotation. Similarly, the camera 46 is coupled to the information processing device 52, receives a control signal from the processing device 52, and supplies the information processing device with an output signal that displays the position of incidence of the reflected light beam 45 on the sensor 50. . The light source 42 is similarly controlled by the processing device 52.
[0008]
The operation of the embodiment of FIG. 1 is shown in FIGS. 2A and 2B. In FIG. 2A, incident beam 44 intersects sealing surface 36 at point A, is reflected at 45, and strikes sensor 50 at point B via lens 48. In FIG. 2B, the beam 44 is incident at a point A ′ in the downward slope or depression 36a in the sealing surface 36. As a result, the reflected light beam 45 passes through the lens 48 and enters the sensor 50 at a different point B ′. Since the sensor 50 supplies an output signal indicating the position of incidence on the sensor to the information processing device 52 (FIG. 1), the output signal in FIG. 2B is different from the signal in FIG. 2A. Accordingly, the information processing device 52 displays the amount of change in the level of the sealing surface at the point of container rotation where the indentation 36a meets, and between the incident reference point B in FIG. 2A and the changed incident point B ′ in FIG. 2B. A display having a size corresponding to the shift is received. If the recess 36a is substantially arcuate in size, the modified sensor output signal of FIG. 2 will be maintained in response to multiple increments of container rotation. On the other hand, if the raised portion 36 b meets the sealing surface, the incident point B ′ of the reflected light beam 45 on the sensor 50 changes in the opposite direction and supplies a corresponding display to the information processing device 52.
[0009]
Thus, the apparatus of FIG. 1 not only changes the level of the sealing surface that indicates a downwardly inclined, distorted or upwardly inclined mouth as the container rotates, but also the sealing surface when the container rotates. The average height also provides a signal to the information processing device 52. Such an average and / or amount of change in the height of the sealing surface may be suitably displayed at 54 and compared to a corresponding standard value or threshold value within the processor 52. If the average sealing surface height is out of specification, or if the strain, down-tilt or up-tilt sealing surface measurements are out of acceptance, a fail signal is generated and the container is removed from the process line. Signals the appropriate exclusion mechanism to exclude from.
[0010]
Since the light source 42 and the sensor 50 are normally disposed above the sealing surface 36 of the container 22 of the station 24, the incident light beam 44 and the reflected light beam 45 are disposed in a plane perpendicular to the reference surface of the sealing surface. The sensor 50 can also include a lateral effect diode with a lateral effect axis in the plane of the incident and reflected light beams. Such a lateral reflect diode supplies an analog signal to the information processing device 52 as an analog signal whose magnitude changes as a function of the position of incidence of the light beam reflected on the diode surface. Alternatively, sensor 50 may comprise a charge coupled device (CCD) array sensor having a plurality of photosensitive elements arranged in a straight line in the plane of the incident and reflected light beams. In such an array, the sensor array is scanned by the information processing device 52, and the incident position of the reflected light beam on the sensor array is determined as a function of the amplitude of the various element output signals. Such array sensors usually consist of linear array sensors, or can consist of matrix array sensors where one row or column is monitored for sealing surface level measurement purposes.
[0011]
FIG. 3 shows a modified inspection station 24a, with a pair of light beams 44 directed downward to a sealing surface and receiving reflected light beams 45 from laterally opposed sides of the container mouth. Light source / sensor modules 56 and 58 are arranged. The paired light source / sensor array of FIG. 3 can also be compared in real time to determine the height characteristics of the container 22 as the output of the light source / sensor modules 56, 58, respectively, as a function of the combined output signals. It has the inherent advantage of That is, the upwardly inclined mouth and the downward slope of the sealing surface 38 are measured as a function of the height difference between the sealing surfaces of the opposite sides of the container mouth, while the strain sealing surface is a function of the sum of the sensor output signals. Can also be identified. In other words, the magnitude of the change in sealing surface height can be displayed at 54 (FIG. 1) and compared to an appropriate standard value or standard for the generation of an exclusion signal.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of an apparatus for detecting a sealing surface of a container according to a presently preferred embodiment of the present invention.
2A is a partial schematic diagram illustrating the operation of the embodiment described in FIG. 1. FIG.
FIG. 2B is a partial schematic diagram illustrating the operation of the embodiment described in FIG. 1;
FIG. 3 is a partial schematic diagram of a modified embodiment of the present invention.
[Explanation of symbols]
20 Conveyor 21 Sliding plate 22 Container 24 Inspection station 25 Center axis 26 Bottle rotation device 28 Encoder 30 Detector 32 Cylindrical body 34 Cylindrical neck (part of mouth)
35 shoulder 36 sealing surface 36a downward slope or depression 38 helical thread 42 light source 44 collimated narrow light energy incident beam 45 reflected light beam 46 camera or light sensor means 48 focusing lens 50 light sensor 52 information processing device That is, change amount detecting means 54 display 56, 58 light source / sensor module

Claims (12)

An inspection device for inspecting a mouth (34) of a container (22), the container (22) being surrounded by an axially facing sealing surface (36) for sealing engagement with a container cap includes an open port and the central axis and (25), said inspection device,
A rotating means (26) for rotating the container (22) around a rotation axis coinciding with the central axis (25);
A light source (42) positioned to deliver an incident beam (44) of light energy onto the sealing surface (36) of the container in the rotating means at an acute angle to the sealing surface (36 );
Optical sensor means (46) arranged to receive light energy (45) reflected by the sealing surface (36) , and detecting level changes (36a, 36b) at the sealing surface (36) of the container. Detection means for (52)
The light source (42) and the light sensor means (46) are disposed above the sealing surface (36) of the container (22), and the incident beam (44) and the sealing surface (36 of the container). In which the beam (45) reflected from the sealing surface (36) is in a plane perpendicular to the sealing surface (36),
Radiation of the sealing surface (36) where the light (44, 45) from the light source (42) to the light sensor means (46) is parallel to the central axis (25) which is the rotational axis of the container (22) and is inspected. In a plane separated by a distance equal to
The incident beam (44) is a narrow collimated beam that intersects the sealing surface (36) at one position or point (A, A ′, A ″), and its reflected light beam (45) is the optical sensor. Hitting the corresponding position or point (B, B ′, B ″) on the means (46),
Said detecting means (52), the corresponding position or point (B, B ', B ") said light sensor means at (46, 50) point on the (B, B', B") of the position of the Configured to detect a change (36a, 36b) in the level of the sealing surface (36) by interpreting it as the actual level of the sealing surface (36) relative to the light source (42) and the light sensor means (46);
The change (36a, 36b) is detected by the detection means (52) as a function of the incident position of the reflected light beam (45) on the light sensor means (46 , 50 ) when the container (22) is rotating. It is the inspection apparatus according to claim and Turkey. A first pair (56) of cooperating first light source (42) and first light sensor means (46), and a second pair (58) of cooperating second light source (42) and second light sensor means (46). Are arranged on opposite sides of the axis of rotation (25) and the respective incident beam (44) and reflected beam (45) are perpendicular to the sealing surface (36) of the container and the width of the container mouth The apparatus of claim 1, wherein the apparatus is in a plane separated from each other by a distance corresponding to .   The change detection means (52) is adapted to detect the level of the sealing surface (36) as a combined function of changes in the incident position of the reflected light beam (45) in each of the first and second pairs (56, 58). The apparatus of claim 2 including means for detecting a change. Each of the first and second pairs (56, 58) provides an electrical signal that varies as a function of the incident position of the associated reflected beam (45), and the change detection means (52) comprises 4. The apparatus of claim 3, comprising means for responding to the sum. Each of the first and second pairs (56, 58) provides an electrical signal that varies as a function of the incident position of the associated reflected beam (45), and the change detection means (52) comprises 4. The apparatus of claim 3, including means for responding to the difference.   6. Apparatus according to any one of the preceding claims, wherein the light sensor means (46) comprises a sensor (50) comprising a lateral effect diode positioned to comprise a lateral effect axis in the plane. . Said light sensor means (46) comprises a sensor (50) having an array of positioning light sensitive element to be placed in the plane, according to any one of claims 1 to 5 . 8. Apparatus according to any one of the preceding claims, wherein the light sensor means (46) comprises a focusing lens (48).   9. A device according to any one of the preceding claims, wherein the light source (42) comprises a laser. A method for inspecting the mouth of a container (22), said container (22) comprising an open mouth surrounded by an axially facing sealing surface (36) for sealing engagement with a container cap and a central shaft ( with 25) and, the method comprising
(A) rotating the container (22) about the axis (25);
(B) While rotating the container, an incident beam (44) of light energy is sent onto the sealing surface (36) of the container at an acute angle with respect to the sealing surface (36) , whereby the sealing surface (36) Reflecting the beam from the sealing surface (36) in a plane perpendicular to
(C) positioning the optical sensor means (46) in the vertical plane to receive the light beam (45) reflected from the sealing surface (36);
(D) providing means (52) for detecting changes (36a, 36b) in the sealing surface (36) of the container (22);
In the above method comprising the steps of:
(A ′) the sealing surface (36) rotating in the region to be inspected moves tangentially along the plane in which the light (44, 45) from the light source (42) to the optical sensor means (46) travels;
(B ′) The incident beam (44) is a narrow collimated beam that intersects the sealing surface (36) at one position or point (A, A ′, A ″), and its reflected light beam (45) is At the corresponding point (B, B ′, B ″) against the optical sensor means (46), the position of this point on the optical sensor means depending on the level of the sealing surface (36) relative to the optical sensor means Change,
(D ′) The position of the point (B, B ′, B ″) on the optical sensor means is interpreted as the actual level of the sealing surface (36) of the container (22) and the change in level (36a, 36b). ) is detected as the function of the change of the incident position in the optical sensor means (46) on the reflected light beam (45) when the container is rotating,
The method as described above. (E) While rotating the container (22), a second narrow collimated beam (44) of light energy at an acute angle with respect to the sealing surface (36) on the sealing surface (36) of the container (22). Sending, wherein the second beam (44) is incident as a point (A, A ') in a second plane perpendicular to the sealing surface (36) and reflected from the sealing surface (36);
(F) in the sealing surface (36) a second light beam (45) to position the second optical sensor means to receive the reflected from, and (g) on the optical sensor means when the container is rotating Detecting a change in the level of the sealing surface (36) of the container as a combined function of a change in the incident position of the reflected light beam (45) ;
The method according to claim 10 , comprising the additional steps of: The method according to claim 11 , wherein the planes are on opposite sides of the axis of rotation (25) at a distance depending on the width of the mouth of the container.

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